Cameras and video cameras use a lens to focus an image. Such lenses typically have an internally threaded outer end for receiving adapter rings or other lens attachments, such as filters, etc.
Lens caps have long been used to cover the open end of the lens, filters, etc. to prevent dust or scratching of the lens or filter surface. Such lens caps have an opaque end wall with two slidable, diametrically opposed, latches on the side edges of the end wall. The latches are spring biased toward a radially outward direction.
In use, the two latches are urged inward by finger pressure until an edge of each latch clears an inner diameter of the lens, filter, adapter ring, etc. to enable the lens cap to be removed from the lens, etc.
When attaching the lens cap, the cap is urged towards the lens or filter until the latch fingers grip and engage the adapter ring or lens. Either finger pressure or snap-in pressure works against the latch springs to move the springs radially inward until the latch edges pass into engagement with the typically single thread on the inner diameter of the adapter ring or lens to mount the lens cap on the lens, filter, etc. by spring force.
The easy attachment and removal of the lens cap from a lens or filter also contributes to a major problem, namely, easy, unintended engagement of the lens cap from the camera lens, such as when placing the camera in a bag, pocket, purse, or inadvertently striking the camera by another object.
What is needed is a camera lens cap which, while is still easily attachable to and removable from a camera lens, filter, adapter ring, etc. provides a secure locking force to minimize unintentional disengagement of a lens cap from the camera lens.